Optical bistability(OB)is capable of rapidly and reversibly transforming a parameter of an optical signal from one state to another,and homologous nonlinear optical bistable devices are core components of high-speed a...Optical bistability(OB)is capable of rapidly and reversibly transforming a parameter of an optical signal from one state to another,and homologous nonlinear optical bistable devices are core components of high-speed all-optical communication and all-optical networks.In this paper,we theoretically investigated the controllable OB from a Fabry-Pérot(FP)cavity with a nonlinear three-dimensional Dirac semimetal(3D DSM)in the terahertz band.The OB stems from the third-order nonlinear bulk conductivity of the 3D DSM and the resonance mode has a positive effect on the generation of OB.This FP cavity structure is able to tune the OB because the transmittance and the reflectance can be modulated by the Fermi energy of the 3D DSM.We believe that this FP cavity configuration could provide a reference concept for realizing tunable bistable devices.展开更多
Since the first observation of parity-time（PT） symmetry in optics, varied interesting phenomena have been discovered in both theories and experiments, such as PT phase transition and unidirectional invisibility, whi...Since the first observation of parity-time（PT） symmetry in optics, varied interesting phenomena have been discovered in both theories and experiments, such as PT phase transition and unidirectional invisibility, which turns PT-symmetric optics into a hotspot in research. Here, we report on the one-way localized Fabry-Pérot（FP） resonance, where a welldesigned PT optical resonator may operate at exceptional points with bidirectional transparency but unidirectional field localization. Overtones of such one-way localized FP resonance can be classified into a blue shifted branch and a red shifted branch. Therefore, the fundamental resonant frequency is not the lowest one. We find that the spatial field distributions of the overtones at the same absolute order are almost the same, even though their frequencies are quite different.展开更多
In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave- length detuning in a single mode Fabry-P6rot laser diode （SMFP-LD）. Results show that the bistabili...In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave- length detuning in a single mode Fabry-P6rot laser diode （SMFP-LD）. Results show that the bistability characteristics of the dominant and injected modes are strongly dependent on the injected input optical power and wavelength detuning in an SMFP-LD. We observe three types of hysteresis loops： counterclockwise, clockwise, and butterfly hysteresis with various loop widths. In the case of a bistability loop caused by injection power, the transition from counterclockwise to clockwise in the hysteresis direction with the wavelength detuning from 0.028 nm to 0.112 nm is observed in a way of butterfly hys- teresis for the dominant mode by increasing the wavelength detuning. The width of hysteresis loop, induced by wavelength detuning is also changed while the injection power is enhanced from -7 dBm to -5 dBm.展开更多
High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching...High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.展开更多
A laser frequency comb with several tens GHz level is demonstrated,based on a Yb-doped femtosecond fiber laser and two low-finesse Fabry-Perot cavities（FPCs） in series.The original 250-MHz mode-line-spacing of the s...A laser frequency comb with several tens GHz level is demonstrated,based on a Yb-doped femtosecond fiber laser and two low-finesse Fabry-Perot cavities（FPCs） in series.The original 250-MHz mode-line-spacing of the source comb is filtered to 4.75 GHz and 23.75 GHz,respectively.According to the multi-beam interferences theory of FPC,the side-mode suppression rate of FPC schemes is in good agreement with our own theoretical results from 27 dB of a single FPC to43 dB of paired FPCs.To maintain long-term stable operation and determine the absolute frequency mode number in the23.75-GHz comb,the Pound-Drever-Hall（PDH） locking technology is utilized.Such stable tens GHz frequency combs have important applications in calibrating astronomical spectrographs with high resolution.展开更多
This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a sola...This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.展开更多
By using a graded-index multimode fiber （GI-MMF） with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry Prot interferometric （MEFPI） strain sensor is f...By using a graded-index multimode fiber （GI-MMF） with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry Prot interferometric （MEFPI） strain sensor is fabricated through chemical etching and fusion splicing. Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air. The maximum reflection of the sensor is enhanced 12 dB than that obtained by etching of the Er- or B-doped fibers. High fringe contrast of 22 dB is obtained. The strain and temperature responses of the MEFPI sensors are investigated in this experiment. Good linearity and high sensitivity are achieved, with wavelength-strain and wavelength-temperature sensitivities of 7.82 pm/με and 5.01 pm/°C, respectively.展开更多
Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an ...Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.展开更多
A novel gain measurement technique based on the integration of the measured amplified spontaneous emission spectrum multiplying a phase function over one longitudinal mode interval is proposed for Fabry-Perot semicond...A novel gain measurement technique based on the integration of the measured amplified spontaneous emission spectrum multiplying a phase function over one longitudinal mode interval is proposed for Fabry-Perot semiconductor lasers.展开更多
We present a transmission-type polarization conversion metamaterial(PCM)whose functions can be dynamically switched among the linear-to-circular(LTC)and linear-to-linear(LTL)polarization conversions.The proposed PCM c...We present a transmission-type polarization conversion metamaterial(PCM)whose functions can be dynamically switched among the linear-to-circular(LTC)and linear-to-linear(LTL)polarization conversions.The proposed PCM consists of a grating,a polarization conversion surface and a reconfigurable polarization selective surface incorporated with PIN diodes.By changing the states of diodes,the PCM can achieve the reconfigurable manipulations for incident waves.The Fabry-Pérot(F-P)resonances excited by the PCM contribute to the polarization conversions,as is illustrated.Moreover,through establishing the F-P-like cavity model and analyzing the electric field components of the transmitted waves,the conditions for realizing LTC polarization conversion are revealed,which can guide the construction of PCM.The prototype of PCM is fabricated and measured,which can achieve LTC and LTL polarization conversions within 3.31-3.56 GHz and 2.76-4.24 GHz,respectively,the polarization conversion ratios of two functions are higher than 0.95.The measurement results are in agreement with the simulation data.展开更多
We investigate theoretically the carrier transport in a two-dimensional topological insulator of(001)HgTe/CdTe quantum-well heterostructure with inverted band,and find distinct switchable features of the transmission ...We investigate theoretically the carrier transport in a two-dimensional topological insulator of(001)HgTe/CdTe quantum-well heterostructure with inverted band,and find distinct switchable features of the transmission spectra in the topological edge states by designing the double-electric modulation potentials.The transmission spectra exhibit the significant Fabry–Pérot resonances for the double-electric transport system.Furthermore,the transmission properties show rich behaviors when the Fermi energy lies in the different locations in the energy spectrum and the double-electric barrier regions.The opacity and transparency of the double-modulated barrier regions can be controlled by tuning the modulated potentials,Fermi energy and the length of modulated regions.This electrical switching behavior can be realized by tuning the voltages applied on the metal gates.The Fabry–Pérot resonances leads to oscillations in the transmission which can be observed in experimentally.This electric modulated-mechanism provides us a realistic way to switch the transmission in edge states which can be constructed in low-power information processing devices.展开更多
基金Project supported by the Wenzhou Major Science and Technology Innovation Project:Research and Industrialization of Key Technologies for Intelligent Dynamic Ultrahigh Pressure Microfluidizer(Grant No.ZG2023012)Wenzhou Major Science and Technology Innovation PR Project(Grant No.ZG2022011)+3 种基金the National Natural Science Foundation of China(Grant No.62305254)the Scientific Research Fund of the Natural Science Foundation of Hunan Province(Grant No.2022JJ30394)the Changsha Natural Science Foundation(Grant Nos.kq2202236 and kq2202246)the Science and Technology Project of Jiangxi Provincial Education Department(Grant No.GJJ190911).
文摘Optical bistability(OB)is capable of rapidly and reversibly transforming a parameter of an optical signal from one state to another,and homologous nonlinear optical bistable devices are core components of high-speed all-optical communication and all-optical networks.In this paper,we theoretically investigated the controllable OB from a Fabry-Pérot(FP)cavity with a nonlinear three-dimensional Dirac semimetal(3D DSM)in the terahertz band.The OB stems from the third-order nonlinear bulk conductivity of the 3D DSM and the resonance mode has a positive effect on the generation of OB.This FP cavity structure is able to tune the OB because the transmittance and the reflectance can be modulated by the Fermi energy of the 3D DSM.We believe that this FP cavity configuration could provide a reference concept for realizing tunable bistable devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674119,11404125,and 11574389)the financial support from the Bird Nest Plan of HUST,Chinasupported by One Hundred-Talent Plan of Chinese Academy of Sciences
文摘Since the first observation of parity-time（PT） symmetry in optics, varied interesting phenomena have been discovered in both theories and experiments, such as PT phase transition and unidirectional invisibility, which turns PT-symmetric optics into a hotspot in research. Here, we report on the one-way localized Fabry-Pérot（FP） resonance, where a welldesigned PT optical resonator may operate at exceptional points with bidirectional transparency but unidirectional field localization. Overtones of such one-way localized FP resonance can be classified into a blue shifted branch and a red shifted branch. Therefore, the fundamental resonant frequency is not the lowest one. We find that the spatial field distributions of the overtones at the same absolute order are almost the same, even though their frequencies are quite different.
基金supported by the National Natural Science Foundation of China(Grant No.61205111)the Open Foundation of State Key Laboratory of Millimeter Waves,China(Grant No.K201219)the Natural Science Foundation of Chongqing Normal University,China(Grant No.2011XLZ06)
文摘In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave- length detuning in a single mode Fabry-P6rot laser diode （SMFP-LD）. Results show that the bistability characteristics of the dominant and injected modes are strongly dependent on the injected input optical power and wavelength detuning in an SMFP-LD. We observe three types of hysteresis loops： counterclockwise, clockwise, and butterfly hysteresis with various loop widths. In the case of a bistability loop caused by injection power, the transition from counterclockwise to clockwise in the hysteresis direction with the wavelength detuning from 0.028 nm to 0.112 nm is observed in a way of butterfly hys- teresis for the dominant mode by increasing the wavelength detuning. The width of hysteresis loop, induced by wavelength detuning is also changed while the injection power is enhanced from -7 dBm to -5 dBm.
基金support from the National Key Research and Development Program of China (2020YFA0714504,2019YFA0709100).
文摘High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.
基金supported by the National Basic Research Program of China(Grant No.2012CB821304)the National Natural Science Foundation of China(Grant Nos.11078022 and 61378040)
文摘A laser frequency comb with several tens GHz level is demonstrated,based on a Yb-doped femtosecond fiber laser and two low-finesse Fabry-Perot cavities（FPCs） in series.The original 250-MHz mode-line-spacing of the source comb is filtered to 4.75 GHz and 23.75 GHz,respectively.According to the multi-beam interferences theory of FPC,the side-mode suppression rate of FPC schemes is in good agreement with our own theoretical results from 27 dB of a single FPC to43 dB of paired FPCs.To maintain long-term stable operation and determine the absolute frequency mode number in the23.75-GHz comb,the Pound-Drever-Hall（PDH） locking technology is utilized.Such stable tens GHz frequency combs have important applications in calibrating astronomical spectrographs with high resolution.
基金financially supported by the Green Science program funded by POSCOthe National Research Foundation(NRF)grants(NRF2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290,and NRF-2018M3D1A1058997)funded by the Ministry of Science and ICT,Republic of Korea+2 种基金the Global Ph.D.fellowship(NRF-2017H1A2A1043204)from the Ministry of Education,Republic of Koreathe PIURI fellowship funded by POSTECHa fellowship from Hyundai Motor Chung Mong-Koo Foundation。
文摘This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.
基金supported by the State Key Laboratory of Advanced Optical Communication Systems and Networks,China
文摘By using a graded-index multimode fiber （GI-MMF） with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry Prot interferometric （MEFPI） strain sensor is fabricated through chemical etching and fusion splicing. Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air. The maximum reflection of the sensor is enhanced 12 dB than that obtained by etching of the Er- or B-doped fibers. High fringe contrast of 22 dB is obtained. The strain and temperature responses of the MEFPI sensors are investigated in this experiment. Good linearity and high sensitivity are achieved, with wavelength-strain and wavelength-temperature sensitivities of 7.82 pm/με and 5.01 pm/°C, respectively.
基金This work was supported by the National "863" Project of China (No. 2003AA311022)the National "973" Project of China (No. 2004CB719804)the National Natural Science Foundation of China (No. 10274108)the Natural Science Foundation of Guangdong Province of China.
文摘Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.
基金This work was supported by the National Nature Science Foundation of China under grants No. 60225011major state basic research program under grant No. G2000036606.
文摘A novel gain measurement technique based on the integration of the measured amplified spontaneous emission spectrum multiplying a phase function over one longitudinal mode interval is proposed for Fabry-Perot semiconductor lasers.
基金Project supported by the Fundamental Research Funds for Central Universities(Grant No.2682020GF03)
文摘We present a transmission-type polarization conversion metamaterial(PCM)whose functions can be dynamically switched among the linear-to-circular(LTC)and linear-to-linear(LTL)polarization conversions.The proposed PCM consists of a grating,a polarization conversion surface and a reconfigurable polarization selective surface incorporated with PIN diodes.By changing the states of diodes,the PCM can achieve the reconfigurable manipulations for incident waves.The Fabry-Pérot(F-P)resonances excited by the PCM contribute to the polarization conversions,as is illustrated.Moreover,through establishing the F-P-like cavity model and analyzing the electric field components of the transmitted waves,the conditions for realizing LTC polarization conversion are revealed,which can guide the construction of PCM.The prototype of PCM is fabricated and measured,which can achieve LTC and LTL polarization conversions within 3.31-3.56 GHz and 2.76-4.24 GHz,respectively,the polarization conversion ratios of two functions are higher than 0.95.The measurement results are in agreement with the simulation data.
基金Project supported by the College Innovation Project of Guangdong Province(Grant No.2020KTSCX329)the Social Public Welfare and Basic Research Project of Zhongshan City(Grant No.2020B2044)+2 种基金Zhongshan Polytechnic Highlevel Talents Project(Grant No.KYG2102)the National Key R&D Program of China(Grant No.2021YFA1200502)the National Natural Science Foundation of China(Grant No.12174423)。
文摘We investigate theoretically the carrier transport in a two-dimensional topological insulator of(001)HgTe/CdTe quantum-well heterostructure with inverted band,and find distinct switchable features of the transmission spectra in the topological edge states by designing the double-electric modulation potentials.The transmission spectra exhibit the significant Fabry–Pérot resonances for the double-electric transport system.Furthermore,the transmission properties show rich behaviors when the Fermi energy lies in the different locations in the energy spectrum and the double-electric barrier regions.The opacity and transparency of the double-modulated barrier regions can be controlled by tuning the modulated potentials,Fermi energy and the length of modulated regions.This electrical switching behavior can be realized by tuning the voltages applied on the metal gates.The Fabry–Pérot resonances leads to oscillations in the transmission which can be observed in experimentally.This electric modulated-mechanism provides us a realistic way to switch the transmission in edge states which can be constructed in low-power information processing devices.
